The invention relates to a filter insert for separating oil out of a flow of gas. Such filter inserts are known, for instance from GB 988 692. If one wants to use this type of filter insert in, for example, internal combustion engines which are to satisfy the latest exhaust regulations and, at the same time, are simple and economical to build and also dispose of, the disadvantage is that this cannot be done because of the complex construction and great number of materials used.
Therefore, it is the object of the invention to improve a filter insert and a device for separating out oil spray of the type named in the introduction in order to create a reliably working device and filter element for separating out oil spray which are simple and economical to produce and dispose of as well.
This object of the invention is solved according to the invention in that the filter insert has a filtered gas side and an unfiltered gas side and means of support and has at least two separation zones of varying degrees of fineness. Because of the reduction of the parts required, cost is lowered for production as well as for the necessary disposal at the end of product life. The use of separation zones of varying degrees of fineness leads to improved separating out of the oil since correspondingly appropriate coalescence surfaces are available for oil drops of different sizes.
An advantageous development of the invention provides that the means of support are permeable to gas. In this way, the support fulfills several functions. On the one hand it functions as a support, on the other hand, depending on its permeability, as an oil separator of great or less coarseness which fulfills the function of separation and drainage of, for example, large oil particles.
In another advantageous development, it is provided that a separation zone is comprised of textile thread. This separation zone, knit, woven or wound as appropriate, is responsible for separating oil droplets which coagulate best on separating elements in the millimeter range. The use of this kind of separating means ensures low loss of pressure at a sufficient degree of oil separation.
In another advantageous development, it is provided that a separation zone is comprised of fibers or filaments which adhere to one another and therefore has a fine portion. This fine portion is responsible for separation of oil in the range of small oil particles. In addition to its separation and drainage functions with regard to the oil in the gas, this zone, also described as fleece, protects the wound separation zone of the filter element which, particularly when made of glass fibers, is very sensitive to mechanical strain; additionally it forms the spatial boundary, as in a housing, in order to do without a further packaging shell.
Another advantageous development provides that the material of the separation zone is made of plastic, such as polyester, polyester amide, polyester acrylic or aromatic polyamide fiber, metal or metal oxide. The use of a textured filament thread is particularly advantageous. The combination in textured thread of low filament diameter and high volume ensures a good result in oil separation, for example, in the aerosol region, since especially in motors, which must satisfy the continually increasing strictness of requirements for pollution burden in exhaust, a high degree of oil separation is important with a low loss of pressure and, at the same time, without the entrance of, for example, particles of soot, where individual fibers preferably are smaller than 10 mm.
Particularly in this size range the separation of oil from aerosol is especially effective.
In another advantageous development, it is provided that the material of at least one of the separation zones has electrostatic characteristics, which improves the process of oil separation.
In another advantageous development of the invention, it is provided that at least one of the separation zones exhibits either hydrophobic or hydrophilic characteristics; this results in a separation behavior in the filter element which can be influenced.
Another advantageous development of the invention provides that in a device for separating out oil spray a filter element can be used. This shows clearly that this type of filter element can be employed universally, for example in pipe cross-sections and/or practically any shaped housing.
In another advantageous development of the invention, it is provided that the device for separating out oil spray can be employed particularly in the intake section of internal combustion engines. The use of a device of this type, in particular in the intake section of an internal combustion engine, is of preventative character with regard to the situation of emissions and pollution within the machine, specially with regard to the life of the functioning elements like, for example, a turbo-supercharger or oil cooler and similar parts.
In another advantageous development of the invention, it is provided that the device for separating out oil can be employed to remove oil from the blow-by gases of an internal combustion engine. For example in diesel motors, mostly with turbo-superchargers, to avoid contact of the admission as well as the turbine blades and other functional elements with gases containing oil in order to avoid damage and also additional pollution burdens.
These and other features of preferred developments of the invention are based not only on the claims but also on the specification and the drawings, where each of the individual characteristics can be realized either alone or together in the form of sub-combinations in the embodiment of the invention and in other fields and can represent embodiments that are advantageous as well as patentable in themselves, for which protection is claimed here.